chore(problems): update LINES problem definition

problems/lines/problem.txt

@@ -15,9 +15,11 @@ Your program should output:
     three
     FOUR
 
-You can use the `split` module to split input by newlines. For example:
+Even though it's not obligatory, you can use the `split` module 
+to split input by newlines. For example:
 
     var split = require('split');
+    var through2 = require('through2');
     process.stdin
         .pipe(split())
         .pipe(through2(function (line, _, next) {
@@ -26,17 +28,22 @@ You can use the `split` module to split input by newlines. For example:
         }))
     ;
 
-`split` will buffer chunks on newlines before you get them. In the previous
-example, we will get separate events for each line even though all the data
+`split` will buffer chunks on newlines before you get them. With example
+above, we will get separate events for each line even though all the data
 probably arrives on the same chunk:
 
     $ echo -e 'one\ntwo\nthree' | node split.js
     'one'
     'two'
     'three'
 
-Your own program should use `split` in this way, but you should transform the
-input and pipe the output through to `process.stdout`.
+Your own program could use `split` in this way, and you should transform the
+input and pipe the output through to `process.stdout`. Keep in mind that,
+if you decide to use this technique, `split2` might be actually needed,
+depending on the versions of the other dependencies.
+
+You are free to solve the challenge without `split` module. In this case,
+you would have to add a new line after each line to have a passing match.
 
 Make sure to `npm install split through2` in the directory where your solution
 file lives.